Bulimic pathology is one of the most common psychiatric problems faced by adolescent girls, shows a persistent course, can result in serious medical complications, and is associated with psychiatric comorbidity and functional impairment. Although longitudinal studies have identified risk factors that increase the likelihood of bulimic pathology, these factors show modest predictive power and little is known about resource factors that decrease risk for bulimic pathology, protective and potentiating factors that mitigate or amplify the effects of risk factors, and how these factors "work together" in a multivariate sense. There have also been few studies on maintenance factors that predict bulimic pathology persistence or the role of psychiatric comorbidity in the etiology and maintenance of this disorder. Further, past studies suffered from certain methodological limitations (e.g., small samples, short follow-up periods, high attrition, mono-reporter data, and sole reliance on survey data). The primary aims of this study are to examine putative risk and resource factors for bulimic pathology and the protective and potentiating factors that moderate these effects, and to test multivariate etiologic models. Secondary aims are to examine putative maintenance factors for bulimic pathology and the role of psychiatric comorbidity in the onset and persistence of this pathology. A tertiary aim is to further document the impact of bulimic pathology on subjective distress, functional impairment, and health care utilization. Aims will be achieved by following a large representative cohort of girls ( N = 496), which has been assessed annually for 4 years since early adolescence (modal age = 13 at T1), for an additional 4 years. When complete, this cohort will have been followed annually for eight years, making it the longest prospective study of adolescent bulimic pathology to date. Key limitations of past studies will be addressed (e.g., by collecting multiple-reporter data and using structured interviews) and advanced quantitative methods will be utilized. Thus, the proposed continuation of this longitudinal study should advance our knowledge of the etiologic and maintenance processes for bulimic pathology and provide direction for the design of prevention and treatment programs for this serious psychiatric problem.